This invention relates generally to the field of data storage devices, and more particularly but not by way of limitation to controlling the aerodynamic excitation imparted to operatively interfacing read/write components by air currents generated by the spinning discs in the disc drive.
Modem disc drives are commonly used in a multitude of computer environments to store large amounts of data in a form that is readily available to a user. Generally, a disc drive has a magnetic disc, or two or more stacked magnetic discs, that are rotated by a motor at high speeds. Each disc has a data storage surface divided into a series of generally concentric data tracks where data is stored in the form of magnetic flux transitions.
A data transfer member such as a magnetic transducer is moved by an actuator to operatively interfacing positions adjacent the data storage surface to sense the magnetic flux transitions in reading data from the disc, and to transmit electrical signals to induce the magnetic flux transitions in writing data to the disc. The active elements of the data transfer member are supported by suspension structures extending from the actuator. The active elements are maintained a small distance above the data storage surface upon an air bearing generated by air currents caused by the spinning discs.
A continuing trend in the industry is toward ever-increasing data storage capacity and processing speed while maintaining or reducing the physical size of the disc drive. Consequently, the data transfer member and supporting structures are continually being miniaturized, and data storage densities are continually being increased. The result is an overall increased sensitivity to vibration, as a percentage of track width. These vibrations can have an adverse effect on the positioning control systems moving the actuator relative to the spinning discs.
One source of excitation that can no longer be disregarded comes from the air currents moving within the disc stack and impinging on disc drive components. The air current velocity, and hence the associated forces, increase in relation to the radial distance from the axis of rotation. Thus, the air currents move faster and are more likely turbulent at outer portions of the discs. Turbulence can impart adverse vibrations, or aerodynamic excitation, to the discs (flutter) and/or to the actuator, particularly to the suspension members (buffeting). Turbulence can also be created by shedding vortices formed from the actuator wake as the airstream flows past the actuator, and also acting on the disc edges as the air currents are expelled from the disc stack. Further, wake excitation from the actuator increases disc vibration.
It has been determined that airstream excitation can be reduced by an airstream conditioning apparatus comprising a finned shroud downstream of the actuator, effecting the three dimensional wake particularly in the region of the actuator and disc read/write interface. It is to this improvement that embodiments of the present invention are directed.
Embodiments of the present invention are directed to an airstream conditioning apparatus for a data storage device. The data storage device has an enclosure supporting a spinning data disc and an actuator operably interfacing with the data disc in a data transfer relationship. The apparatus comprises a shroud supportable in the enclosure downstream of the actuator with respect to air currents generated by the spinning disc, laminarizing the flow and reducing three dimensional effects of the wake in the enclosure at the disc and actuator interface. The shroud furthermore comprises a fin extending from the shroud and terminating in a closely fitting relationship with the disc edge preventing coupling of air currents in spaces between adjacent discs.